Lighting for the Classroom of the Future: Acceptability of Glare

该项目将调查显示屏上的眩光，这是未来教室照明的一个关键因素。这将通过使用显示屏上眩光的可接受性的主观评级来完成，从中确定照明设计的限制标准，从而测试当前英国标准中给出的限制标准不再有效的预测。教育和技能部（DfES）最近推出了两项旨在提供鼓舞人心和可持续教育设施的举措。未来教室计划于2003年启动，旨在试验设计21世纪世纪教育环境的新思路。2004年启动了“为未来建设学校”方案，在10至15年的时间里更新英格兰的每一所中学。未来的课堂将利用信息和通信技术（ICT）的发展，朝着以学习者为中心而不是以教师为中心的学习模式演变。信息和通信技术的使用日益增加，需要扩大提供显示屏设备，这是信息和通信技术的视觉界面，这些自发光物体需要与传统的纸质任务不同的照明考虑。视觉环境，从而室内照明，影响学习者感知视觉刺激的能力，影响他/她的心理态度，从而影响表现。因此，需要对教室照明策略进行审查，以补充新的教学方法的建议。这一需求可以通过2006年光与照明协会宣布他们打算审查教育设施的设计指南来确定。初步研究包括对十所学校的教师和学生进行调查。他们的回答揭示了在交互式白板和PC屏幕上隐藏反射的问题。杂光反射是由明亮表面的反射引起的眩光，例如光源或PC屏幕上的窗口反射。这会导致字符与背景的对比度降低，降低屏幕字符的清晰度，极端情况下会导致屏幕内容无法识别。在英国，照明指南LG 5为教室提供照明设计指导。对于DSE上的眩光控制，LG 5是指LG 3，其根据房间中使用的DSE屏幕的分类规定了灯具亮度的限制。根据BS 9241-7：1998和BS 13406-2：2002中规定的测试，DSE屏幕被分配到三个类别中的一个。对于正极性屏幕，对于I类和II类屏幕，灯具亮度的限值高达1500 cd/m2。然而，最近的测试表明，由于屏幕技术的不断改进，更高的屏幕亮度是可以容忍的。此外，对于使用交互式白板的房间照明没有指导方针，交互式白板是未来教室中的全班界面。因此，需要审查和更新用于定义屏幕类别的阈值，和/或修改这些类别中的照明器亮度的限制。这将使照明设计更具灵活性，从而更加关注整体视觉环境和能源消耗。谢菲尔德大学的未来教室照明项目正在调查几个问题，包括设计照明以适应各种同时进行的任务、使用视觉性能和视觉可接受性模型来预测适当的设计条件、调查屏幕眩光和考虑能源消耗。该提案寻求资金来开展调查其中一个问题所需的实验工作，即测量DSE上面纱反射的可接受性。

This project will investigate glare on display screens, a critical factor for lighting in the classroom of the future. This will be done using subjective ratings of the acceptability of glare on display screens, from which to identify the limiting criteria for lighting design, and thus testing the prediction that the limiting criteria given in current British Standards are no longer valid.The Department for Education and Skills (DfES) has recently launched two initiatives which aim to deliver inspiring and sustainable educational facilities. The Classrooms of the Future programme was initiated in 2003 to experiment with new ideas for designing educational environments for the 21st Century. The Building Schools for the Future programme was launched in 2004 to renew every secondary school in England over a 10-15 year period. The classroom of the future will take advantage of developments in Information and Communication Technology (ICT), an evolution toward learner-centred rather than teacher-centred modes of learning. Increased use of ICT will necessitate expansion in provision of Display Screen Equipment (DSE), the visual interface for ICT, and these self-illuminated objects demand different lighting considerations to traditional paper-based tasks.The visual environment, and hence interior lighting, affects a learner's ability to perceive visual stimuli and affects his/her mental attitude, and thus affects performance. Therefore, a review of strategies for classroom lighting is needed to complement proposals for new approaches to teaching and learning. This need can be identified through the announcement in 2006 from the Society for Light & Lighting of their intention to review design guidance for educational facilities. Preliminary research has included a survey teachers and pupils from ten schools. Their responses reveal problems of veiling reflections on interactive whiteboards and PC screens. Veiling reflection is glare caused by the reflectance of a bright surface, such as a light source or window reflected on the screen of a PC. This can cause a reduction in character-to-background contrast, reducing the legibility of screen characters, which at the extreme can cause the contents of the screen to become unrecognisable.In the UK, Lighting Guide LG5 gives lighting design guidance for classrooms. For the control of glare on DSE, LG5 refers to LG3 which prescribes limits for the luminance of luminaires according to the classification of the DSE screens used in the room. DSE screens are allocated into one of three categories according to tests prescribed in BS 9241-7:1998 and BS 13406-2:2002. For positive polarity screens, the limits of luminaire luminance are up to 1500 cd/m2 for screen categories I and II. However, recent tests have shown that much higher screen luminances are tolerable, due to progressive improvements in screen technology. Furthermore, there are no guidelines for lighting in rooms using interactive whiteboards, the whole-class interface in the classroom of the future. Therefore, there is a need to review and update the thresholds used to define screen categories, and/or to revise the limits of luminaire luminance in these categories. This would allow more flexibility in lighting design, allowing more attention to be paid to the overall visual environment and energy consumption. The Lighting for the Classroom of the Future project at the University of Sheffield is investigating several issues including designing lighting to accommodate a variety of simultaneous tasks, using visual performance and visual acceptability models to predict appropriate design conditions, investigation of screen glare and consideration of energy consumption. This proposal seeks funding to carry out the experimental work needed to investigate one of these issues, that of measuring the acceptability of veiling reflections on DSE.